Waste heat recovery (WHR) systems may recover waste heat energy from an internal combustion engine that would otherwise be lost. The more waste heat energy extracted from an internal combustion engine by a WHR system, the greater the potential efficiency of the engine. In other words, rather than the extracted heat being lost, the extracted heat energy may be repurposed to, for example, supplement the power output by the internal combustion engine, thereby increasing the efficiency of the system. During operation of the WHR system, various operating characteristics may be monitored. However, monitoring the operating characteristics of the WHR system requires sensors that are able to withstand the high temperatures and pressures within a hot section of the WHR system, and are therefore typically costly, difficult to install, and difficult to maintain in an appropriate operating condition.